package demos;

import java.util.Collections;
import java.util.HashSet;
import java.util.Vector;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.CopyOnWriteArraySet;

public class CollectionDemo {
    public static void main(String[] args) {

    }
}
